Remove generate proto task link to compile on

[rougsig]

Java/kotlin: compile task implicit depends on generate proto task via source sets
Android: compile tasks depends on generate proto task via registerJavaGeneratingTask

[ejona86]

If you remove this, then you need to add in OutputFiles for the descriptor and for .zip outputs. The way I did that before:

• For DescriptorSetOptions, make path an @Input and make a new method that returns the non-null output file name. That new method gets @OutputFile.
• I made PluginOptions non-static which requires passing a factory method to domainObjectContainer for builtins and plugins. Then I made two @Optional methods in PluginOptions, one that was OutputFile and one that was `OutputDirectory. This approach takes some refactoring, but overall seemed cleaner
  • The quicker approach is to add a new method getOutputSourceFiles() that has @OutputFiles and returns the files filtered during getOutputSourceDirectories()

[rougsig]

What problem are we trying to solve with this logic? Looks too complicated.

[ejona86]

All the outputs need to be tracked. If you remove the output base dir as an output, then you must track all the individual files/directories. But getOutputSourceDirectories() doesn't return any of the files. Thus you need some other mechanism to expose the output files. There's multiple ways to do that.

[rougsig]

Plugins/Buildins generate files in subfolders. Descriptor is tracked by getDescriptorSetOptionsForCaching. Does anything write files directly to outputBaseDir?

[ejona86]

Plugins/Buildins generate files in subfolders

Often. But protoc can also generate a zip or jar file directly. Those outputs are filtered out from getOutputSourceDirectories().

Descriptor is tracked by getDescriptorSetOptionsForCaching

Not entirely. DescriptorSetOptions.path is an @OutputFile, but it is only used if the user overrides the path. If the user uses the default path then that path would be untracked.

[rougsig]

I see comments in the code

protoc is capable of output generated files directly to a JAR file or ZIP archive if the output location ends with .jar/.zip

However, I do not see any documentation of this feature in the protobuf-gradle-plugin. I also do not see any tests for this feature.

[rougsig]

Not entirely. DescriptorSetOptions.path is an @OutputFile, but it is only used if the user overrides the path. If the user uses the default path then that path would be untracked.

Sounds like a bug, doesn't it?

[ejona86]

I do not see any documentation of this feature in the protobuf-gradle-plugin

All the background I see: #480 and #533 .

Sounds like a bug, doesn't it?

Not on master. If there is an output descriptor, then it is either a child of the base directory or it is the user-configured name. This PR removes the base directory as an output so that introduces a bug.